1. Field of the invention
The present invention relates to an apparatus for mounting surface mounting components onto a circuit board.
2. Description of the prior art
Vacuum suction type pick-and-place devices are generally used to mount surface mounting components onto a circuit board. Japanese Patent Laid-Open Gazette No. 63-178597 shows an example. The picked-up parts are often shifted in position and angle from the state proper position on the suction nozzle. Accordingly, even if the center of the nozzle coincides with the center of the land pattern of the board, the parts are not necessarily put on the right place. Therefore, the positions of the parts must be corrected before mounting. There are two ways of parts position correction. The first is correction of parts position and direction using jaws. Such a device is disclosed in Japanese Patent Laid-Open Gazette No. 63-178597. In this, device the nozzle and the jaws are respectively supported on different structures; the nozzle on a movable structure and the jaws on a immobile one. The device in Japanese Patent Laid-Open Gazette No. 62-111496 is a variation of this type, in which a nozzle and jaws are supported on one movable structure.
In the second method parts position correction is done by adjusting the positional relationship between the nozzle and the circuit board, not that of the nozzle and parts. In this method, it is necessary to know the position of the parts relative to the nozzle by image recognition. An example of this type of device is shown in Japanese Patent Laid-Open Gazette No. 58-213496.
Furthermore, devices with nozzle changeability to handle a wide variety of parts have been developed. Examples of this sort of machine are seen in documents such as Japanese Patent Laid-Open Gazette Nos. 59-69992, 63-16700 and 1-121138.
Therefore, a principle object of the present invention is to provide a novel parts mounting apparatus.
Another object of the present invention is to provide a parts mounting apparatus capable of selectively using normal nozzles and nozzles for image recognition.
Another object of the present invention is to provide a parts mounting apparatus having jaws on the nozzle-supporting structure to mechanically position parts held on a normal nozzle during nozzle travel. These jaws are kept inactive during the use of a nozzle for image recognition.
A parts mounting apparatus in accordance with the present invention comprises a spindle (31) vertically held and having a vacuum suction path (36) inside; a group nozzles (50, 141) selectively mounted on the lower end of said spindle and made to have communication with said vacuum suction path; a nozzle for image recognition (141) included in the above mentioned nozzle group; parts positioning jaws (61a, 61b, 62a, 62b) supported on a structure (34) for centering parts sucked by a normal nozzle with their tips, the same structure also supporting said spindle being able to move upward/downward; means (30, 90, 93, 201, 208) for applying to the spindle vertical motion for picking and placing the parts; means (30, 67, 201, 208) for causing said jaws open/close movement,; and means (30, 90, 93, 201, 208) for preventing the jaws from performing the centering operation.
The spindle with a normal nozzle is raised to the upper limit of the stroke after picking up a parts, and the jaws position the part. When a nozzle for image recognition is in the place of normal nozzle, the spindle ends its upward movement before it reaches the upper limit, and the nozzle for image recognition, which has no need for mechanical positioning of parts, does not enter the working area of jaws. Consequently, the parts positioning jaws do not perform a part centering operation when the nozzle for image recognition is used.
According to the present invention, a parts mounting apparatus can be used with a nozzle for image recognition being mounted on the head portion provided with parts positioning jaws, thereby the function of the machine is enhanced.
The objects and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the embodiments of the present invention when taken in conjunction with accompanying drawings.